1# SPDX-License-Identifier: GPL-2.0 2# Backward compatibility 3asflags-y += $(EXTRA_AFLAGS) 4ccflags-y += $(EXTRA_CFLAGS) 5cppflags-y += $(EXTRA_CPPFLAGS) 6ldflags-y += $(EXTRA_LDFLAGS) 7 8# flags that take effect in current and sub directories 9KBUILD_AFLAGS += $(subdir-asflags-y) 10KBUILD_CFLAGS += $(subdir-ccflags-y) 11 12# Figure out what we need to build from the various variables 13# =========================================================================== 14 15# When an object is listed to be built compiled-in and modular, 16# only build the compiled-in version 17obj-m := $(filter-out $(obj-y),$(obj-m)) 18 19# Libraries are always collected in one lib file. 20# Filter out objects already built-in 21lib-y := $(filter-out $(obj-y), $(sort $(lib-y) $(lib-m))) 22 23# Subdirectories we need to descend into 24subdir-ym := $(sort $(subdir-y) $(subdir-m) \ 25 $(patsubst %/,%, $(filter %/, $(obj-y) $(obj-m)))) 26 27# Handle objects in subdirs: 28# - If we encounter foo/ in $(obj-y), replace it by foo/built-in.a and 29# foo/modules.order 30# - If we encounter foo/ in $(obj-m), replace it by foo/modules.order 31# 32# Generate modules.order to determine modorder. Unfortunately, we don't have 33# information about ordering between -y and -m subdirs. Just put -y's first. 34 35ifdef need-modorder 36obj-m := $(patsubst %/,%/modules.order, $(filter %/, $(obj-y)) $(obj-m)) 37else 38obj-m := $(filter-out %/, $(obj-m)) 39endif 40 41ifdef need-builtin 42obj-y := $(patsubst %/, %/built-in.a, $(obj-y)) 43else 44obj-y := $(filter-out %/, $(obj-y)) 45endif 46 47# Expand $(foo-objs) $(foo-y) by calling $(call suffix-search,foo.o,-objs -y) 48suffix-search = $(foreach s,$(2),$($(1:.o=$s))) 49# If $(foo-objs), $(foo-y), $(foo-m), or $(foo-) exists, foo.o is a composite object 50multi-search = $(sort $(foreach m,$(1), $(if $(strip $(call suffix-search,$(m),$(2) -)), $(m)))) 51multi-used-y := $(call multi-search,$(obj-y),-objs -y) 52multi-used-m := $(call multi-search,$(obj-m),-objs -y -m) 53multi-used := $(multi-used-y) $(multi-used-m) 54 55# Replace multi-part objects by their individual parts, 56# including built-in.a from subdirectories 57real-search = $(foreach m,$(1), $(if $(strip $(call suffix-search,$(m),$(2) -)),$(call suffix-search,$(m),$(2)),$(m))) 58real-obj-y := $(call real-search, $(obj-y),-objs -y) 59real-obj-m := $(call real-search, $(obj-m),-objs -y -m) 60 61always-y += $(always-m) 62 63# hostprogs-always-y += foo 64# ... is a shorthand for 65# hostprogs += foo 66# always-y += foo 67hostprogs += $(hostprogs-always-y) $(hostprogs-always-m) 68always-y += $(hostprogs-always-y) $(hostprogs-always-m) 69 70# userprogs-always-y is likewise. 71userprogs += $(userprogs-always-y) $(userprogs-always-m) 72always-y += $(userprogs-always-y) $(userprogs-always-m) 73 74# DTB 75# If CONFIG_OF_ALL_DTBS is enabled, all DT blobs are built 76always-y += $(dtb-y) 77always-$(CONFIG_OF_ALL_DTBS) += $(dtb-) 78 79ifneq ($(CHECK_DTBS),) 80always-y += $(patsubst %.dtb,%.dt.yaml, $(dtb-y)) 81always-y += $(patsubst %.dtbo,%.dt.yaml, $(dtb-y)) 82always-$(CONFIG_OF_ALL_DTBS) += $(patsubst %.dtb,%.dt.yaml, $(dtb-)) 83always-$(CONFIG_OF_ALL_DTBS) += $(patsubst %.dtbo,%.dt.yaml, $(dtb-)) 84endif 85 86# Add subdir path 87 88extra-y := $(addprefix $(obj)/,$(extra-y)) 89always-y := $(addprefix $(obj)/,$(always-y)) 90targets := $(addprefix $(obj)/,$(targets)) 91obj-m := $(addprefix $(obj)/,$(obj-m)) 92lib-y := $(addprefix $(obj)/,$(lib-y)) 93real-obj-y := $(addprefix $(obj)/,$(real-obj-y)) 94real-obj-m := $(addprefix $(obj)/,$(real-obj-m)) 95multi-used-m := $(addprefix $(obj)/,$(multi-used-m)) 96subdir-ym := $(addprefix $(obj)/,$(subdir-ym)) 97 98# Finds the multi-part object the current object will be linked into. 99# If the object belongs to two or more multi-part objects, list them all. 100modname-multi = $(sort $(foreach m,$(multi-used),\ 101 $(if $(filter $*.o, $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m))),$(m:.o=)))) 102 103__modname = $(if $(modname-multi),$(modname-multi),$(basetarget)) 104 105modname = $(subst $(space),:,$(__modname)) 106modfile = $(addprefix $(obj)/,$(__modname)) 107 108# target with $(obj)/ and its suffix stripped 109target-stem = $(basename $(patsubst $(obj)/%,%,$@)) 110 111# These flags are needed for modversions and compiling, so we define them here 112# $(modname_flags) defines KBUILD_MODNAME as the name of the module it will 113# end up in (or would, if it gets compiled in) 114name-fix-token = $(subst $(comma),_,$(subst -,_,$1)) 115name-fix = $(call stringify,$(call name-fix-token,$1)) 116basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget)) 117modname_flags = -DKBUILD_MODNAME=$(call name-fix,$(modname)) \ 118 -D__KBUILD_MODNAME=kmod_$(call name-fix-token,$(modname)) 119modfile_flags = -DKBUILD_MODFILE=$(call stringify,$(modfile)) 120 121_c_flags = $(filter-out $(CFLAGS_REMOVE_$(target-stem).o), \ 122 $(filter-out $(ccflags-remove-y), \ 123 $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(ccflags-y)) \ 124 $(CFLAGS_$(target-stem).o)) 125_a_flags = $(filter-out $(AFLAGS_REMOVE_$(target-stem).o), \ 126 $(filter-out $(asflags-remove-y), \ 127 $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) $(asflags-y)) \ 128 $(AFLAGS_$(target-stem).o)) 129_cpp_flags = $(KBUILD_CPPFLAGS) $(cppflags-y) $(CPPFLAGS_$(target-stem).lds) 130 131# 132# Enable gcov profiling flags for a file, directory or for all files depending 133# on variables GCOV_PROFILE_obj.o, GCOV_PROFILE and CONFIG_GCOV_PROFILE_ALL 134# (in this order) 135# 136ifeq ($(CONFIG_GCOV_KERNEL),y) 137_c_flags += $(if $(patsubst n%,, \ 138 $(GCOV_PROFILE_$(basetarget).o)$(GCOV_PROFILE)$(CONFIG_GCOV_PROFILE_ALL)), \ 139 $(CFLAGS_GCOV)) 140endif 141 142# 143# Enable address sanitizer flags for kernel except some files or directories 144# we don't want to check (depends on variables KASAN_SANITIZE_obj.o, KASAN_SANITIZE) 145# 146ifeq ($(CONFIG_KASAN),y) 147ifneq ($(CONFIG_KASAN_HW_TAGS),y) 148_c_flags += $(if $(patsubst n%,, \ 149 $(KASAN_SANITIZE_$(basetarget).o)$(KASAN_SANITIZE)y), \ 150 $(CFLAGS_KASAN), $(CFLAGS_KASAN_NOSANITIZE)) 151endif 152endif 153 154ifeq ($(CONFIG_UBSAN),y) 155_c_flags += $(if $(patsubst n%,, \ 156 $(UBSAN_SANITIZE_$(basetarget).o)$(UBSAN_SANITIZE)$(CONFIG_UBSAN_SANITIZE_ALL)), \ 157 $(CFLAGS_UBSAN)) 158endif 159 160ifeq ($(CONFIG_KCOV),y) 161_c_flags += $(if $(patsubst n%,, \ 162 $(KCOV_INSTRUMENT_$(basetarget).o)$(KCOV_INSTRUMENT)$(CONFIG_KCOV_INSTRUMENT_ALL)), \ 163 $(CFLAGS_KCOV)) 164endif 165 166# 167# Enable KCSAN flags except some files or directories we don't want to check 168# (depends on variables KCSAN_SANITIZE_obj.o, KCSAN_SANITIZE) 169# 170ifeq ($(CONFIG_KCSAN),y) 171_c_flags += $(if $(patsubst n%,, \ 172 $(KCSAN_SANITIZE_$(basetarget).o)$(KCSAN_SANITIZE)y), \ 173 $(CFLAGS_KCSAN)) 174endif 175 176# $(srctree)/$(src) for including checkin headers from generated source files 177# $(objtree)/$(obj) for including generated headers from checkin source files 178ifeq ($(KBUILD_EXTMOD),) 179ifdef building_out_of_srctree 180_c_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj) 181_a_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj) 182_cpp_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj) 183endif 184endif 185 186part-of-module = $(if $(filter $(basename $@).o, $(real-obj-m)),y) 187quiet_modtag = $(if $(part-of-module),[M], ) 188 189modkern_cflags = \ 190 $(if $(part-of-module), \ 191 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \ 192 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL) $(modfile_flags)) 193 194modkern_aflags = $(if $(part-of-module), \ 195 $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE), \ 196 $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL)) 197 198c_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \ 199 -include $(srctree)/include/linux/compiler_types.h \ 200 $(_c_flags) $(modkern_cflags) \ 201 $(basename_flags) $(modname_flags) 202 203a_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \ 204 $(_a_flags) $(modkern_aflags) 205 206cpp_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \ 207 $(_cpp_flags) 208 209ld_flags = $(KBUILD_LDFLAGS) $(ldflags-y) $(LDFLAGS_$(@F)) 210 211DTC_INCLUDE := $(srctree)/scripts/dtc/include-prefixes 212 213dtc_cpp_flags = -Wp,-MMD,$(depfile).pre.tmp -nostdinc \ 214 $(addprefix -I,$(DTC_INCLUDE)) \ 215 -undef -D__DTS__ 216 217# Objtool arguments are also needed for modfinal with LTO, so we define 218# then here to avoid duplication. 219objtool_args = \ 220 $(if $(CONFIG_UNWINDER_ORC),orc generate,check) \ 221 $(if $(part-of-module), --module,) \ 222 $(if $(CONFIG_FRAME_POINTER),, --no-fp) \ 223 $(if $(or $(CONFIG_GCOV_KERNEL),$(CONFIG_LTO_CLANG)), \ 224 --no-unreachable,) \ 225 $(if $(CONFIG_RETPOLINE), --retpoline,) \ 226 $(if $(CONFIG_X86_SMAP), --uaccess,) \ 227 $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount,) 228 229# Useful for describing the dependency of composite objects 230# Usage: 231# $(call multi_depend, multi_used_targets, suffix_to_remove, suffix_to_add) 232define multi_depend 233$(foreach m, $(notdir $1), \ 234 $(eval $(obj)/$m: \ 235 $(addprefix $(obj)/, $(foreach s, $3, $($(m:%$(strip $2)=%$(s))))))) 236endef 237 238quiet_cmd_copy = COPY $@ 239 cmd_copy = cp $< $@ 240 241# Shipped files 242# =========================================================================== 243 244quiet_cmd_shipped = SHIPPED $@ 245cmd_shipped = cat $< > $@ 246 247$(obj)/%: $(src)/%_shipped 248 $(call cmd,shipped) 249 250# Commands useful for building a boot image 251# =========================================================================== 252# 253# Use as following: 254# 255# target: source(s) FORCE 256# $(if_changed,ld/objcopy/gzip) 257# 258# and add target to 'targets' so that we know we have to 259# read in the saved command line 260 261# Linking 262# --------------------------------------------------------------------------- 263 264quiet_cmd_ld = LD $@ 265 cmd_ld = $(LD) $(ld_flags) $(real-prereqs) -o $@ 266 267# Archive 268# --------------------------------------------------------------------------- 269 270quiet_cmd_ar = AR $@ 271 cmd_ar = rm -f $@; $(AR) cDPrsT $@ $(real-prereqs) 272 273# Objcopy 274# --------------------------------------------------------------------------- 275 276quiet_cmd_objcopy = OBJCOPY $@ 277cmd_objcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@ 278 279# Gzip 280# --------------------------------------------------------------------------- 281 282quiet_cmd_gzip = GZIP $@ 283 cmd_gzip = cat $(real-prereqs) | $(KGZIP) -n -f -9 > $@ 284 285# DTC 286# --------------------------------------------------------------------------- 287DTC ?= $(objtree)/scripts/dtc/dtc 288DTC_FLAGS += -Wno-interrupt_provider 289 290# Disable noisy checks by default 291ifeq ($(findstring 1,$(KBUILD_EXTRA_WARN)),) 292DTC_FLAGS += -Wno-unit_address_vs_reg \ 293 -Wno-unit_address_format \ 294 -Wno-avoid_unnecessary_addr_size \ 295 -Wno-alias_paths \ 296 -Wno-graph_child_address \ 297 -Wno-simple_bus_reg \ 298 -Wno-unique_unit_address \ 299 -Wno-pci_device_reg 300endif 301 302ifneq ($(findstring 2,$(KBUILD_EXTRA_WARN)),) 303DTC_FLAGS += -Wnode_name_chars_strict \ 304 -Wproperty_name_chars_strict \ 305 -Winterrupt_provider 306endif 307 308DTC_FLAGS += $(DTC_FLAGS_$(basetarget)) 309 310# Generate an assembly file to wrap the output of the device tree compiler 311quiet_cmd_dt_S_dtb= DTB $@ 312cmd_dt_S_dtb= \ 313{ \ 314 echo '\#include <asm-generic/vmlinux.lds.h>'; \ 315 echo '.section .dtb.init.rodata,"a"'; \ 316 echo '.balign STRUCT_ALIGNMENT'; \ 317 echo '.global __dtb_$(subst -,_,$(*F))_begin'; \ 318 echo '__dtb_$(subst -,_,$(*F))_begin:'; \ 319 echo '.incbin "$<" '; \ 320 echo '__dtb_$(subst -,_,$(*F))_end:'; \ 321 echo '.global __dtb_$(subst -,_,$(*F))_end'; \ 322 echo '.balign STRUCT_ALIGNMENT'; \ 323} > $@ 324 325$(obj)/%.dtb.S: $(obj)/%.dtb FORCE 326 $(call if_changed,dt_S_dtb) 327 328quiet_cmd_dtc = DTC $@ 329cmd_dtc = $(HOSTCC) -E $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \ 330 $(DTC) -O $(patsubst .%,%,$(suffix $@)) -o $@ -b 0 \ 331 $(addprefix -i,$(dir $<) $(DTC_INCLUDE)) $(DTC_FLAGS) \ 332 -d $(depfile).dtc.tmp $(dtc-tmp) ; \ 333 cat $(depfile).pre.tmp $(depfile).dtc.tmp > $(depfile) 334 335$(obj)/%.dtb: $(src)/%.dts $(DTC) FORCE 336 $(call if_changed_dep,dtc) 337 338$(obj)/%.dtbo: $(src)/%.dts $(DTC) FORCE 339 $(call if_changed_dep,dtc) 340 341DT_CHECKER ?= dt-validate 342DT_BINDING_DIR := Documentation/devicetree/bindings 343# DT_TMP_SCHEMA may be overridden from Documentation/devicetree/bindings/Makefile 344DT_TMP_SCHEMA ?= $(objtree)/$(DT_BINDING_DIR)/processed-schema.json 345 346quiet_cmd_dtb_check = CHECK $@ 347 cmd_dtb_check = $(DT_CHECKER) -u $(srctree)/$(DT_BINDING_DIR) -p $(DT_TMP_SCHEMA) $@ 348 349define rule_dtc 350 $(call cmd_and_fixdep,dtc) 351 $(call cmd,dtb_check) 352endef 353 354$(obj)/%.dt.yaml: $(src)/%.dts $(DTC) $(DT_TMP_SCHEMA) FORCE 355 $(call if_changed_rule,dtc,yaml) 356 357dtc-tmp = $(subst $(comma),_,$(dot-target).dts.tmp) 358 359# Bzip2 360# --------------------------------------------------------------------------- 361 362# Bzip2 and LZMA do not include size in file... so we have to fake that; 363# append the size as a 32-bit littleendian number as gzip does. 364size_append = printf $(shell \ 365dec_size=0; \ 366for F in $(real-prereqs); do \ 367 fsize=$$($(CONFIG_SHELL) $(srctree)/scripts/file-size.sh $$F); \ 368 dec_size=$$(expr $$dec_size + $$fsize); \ 369done; \ 370printf "%08x\n" $$dec_size | \ 371 sed 's/\(..\)/\1 /g' | { \ 372 read ch0 ch1 ch2 ch3; \ 373 for ch in $$ch3 $$ch2 $$ch1 $$ch0; do \ 374 printf '%s%03o' '\\' $$((0x$$ch)); \ 375 done; \ 376 } \ 377) 378 379quiet_cmd_bzip2 = BZIP2 $@ 380 cmd_bzip2 = { cat $(real-prereqs) | $(KBZIP2) -9; $(size_append); } > $@ 381 382# Lzma 383# --------------------------------------------------------------------------- 384 385quiet_cmd_lzma = LZMA $@ 386 cmd_lzma = { cat $(real-prereqs) | $(LZMA) -9; $(size_append); } > $@ 387 388quiet_cmd_lzo = LZO $@ 389 cmd_lzo = { cat $(real-prereqs) | $(KLZOP) -9; $(size_append); } > $@ 390 391quiet_cmd_lz4 = LZ4 $@ 392 cmd_lz4 = { cat $(real-prereqs) | $(LZ4) -l -c1 stdin stdout; \ 393 $(size_append); } > $@ 394 395# U-Boot mkimage 396# --------------------------------------------------------------------------- 397 398MKIMAGE := $(srctree)/scripts/mkuboot.sh 399 400# SRCARCH just happens to match slightly more than ARCH (on sparc), so reduces 401# the number of overrides in arch makefiles 402UIMAGE_ARCH ?= $(SRCARCH) 403UIMAGE_COMPRESSION ?= $(if $(2),$(2),none) 404UIMAGE_OPTS-y ?= 405UIMAGE_TYPE ?= kernel 406UIMAGE_LOADADDR ?= arch_must_set_this 407UIMAGE_ENTRYADDR ?= $(UIMAGE_LOADADDR) 408UIMAGE_NAME ?= 'Linux-$(KERNELRELEASE)' 409 410quiet_cmd_uimage = UIMAGE $@ 411 cmd_uimage = $(BASH) $(MKIMAGE) -A $(UIMAGE_ARCH) -O linux \ 412 -C $(UIMAGE_COMPRESSION) $(UIMAGE_OPTS-y) \ 413 -T $(UIMAGE_TYPE) \ 414 -a $(UIMAGE_LOADADDR) -e $(UIMAGE_ENTRYADDR) \ 415 -n $(UIMAGE_NAME) -d $< $@ 416 417# XZ 418# --------------------------------------------------------------------------- 419# Use xzkern to compress the kernel image and xzmisc to compress other things. 420# 421# xzkern uses a big LZMA2 dictionary since it doesn't increase memory usage 422# of the kernel decompressor. A BCJ filter is used if it is available for 423# the target architecture. xzkern also appends uncompressed size of the data 424# using size_append. The .xz format has the size information available at 425# the end of the file too, but it's in more complex format and it's good to 426# avoid changing the part of the boot code that reads the uncompressed size. 427# Note that the bytes added by size_append will make the xz tool think that 428# the file is corrupt. This is expected. 429# 430# xzmisc doesn't use size_append, so it can be used to create normal .xz 431# files. xzmisc uses smaller LZMA2 dictionary than xzkern, because a very 432# big dictionary would increase the memory usage too much in the multi-call 433# decompression mode. A BCJ filter isn't used either. 434quiet_cmd_xzkern = XZKERN $@ 435 cmd_xzkern = { cat $(real-prereqs) | sh $(srctree)/scripts/xz_wrap.sh; \ 436 $(size_append); } > $@ 437 438quiet_cmd_xzmisc = XZMISC $@ 439 cmd_xzmisc = cat $(real-prereqs) | $(XZ) --check=crc32 --lzma2=dict=1MiB > $@ 440 441# ZSTD 442# --------------------------------------------------------------------------- 443# Appends the uncompressed size of the data using size_append. The .zst 444# format has the size information available at the beginning of the file too, 445# but it's in a more complex format and it's good to avoid changing the part 446# of the boot code that reads the uncompressed size. 447# 448# Note that the bytes added by size_append will make the zstd tool think that 449# the file is corrupt. This is expected. 450# 451# zstd uses a maximum window size of 8 MB. zstd22 uses a maximum window size of 452# 128 MB. zstd22 is used for kernel compression because it is decompressed in a 453# single pass, so zstd doesn't need to allocate a window buffer. When streaming 454# decompression is used, like initramfs decompression, zstd22 should likely not 455# be used because it would require zstd to allocate a 128 MB buffer. 456 457quiet_cmd_zstd = ZSTD $@ 458 cmd_zstd = { cat $(real-prereqs) | $(ZSTD) -19; $(size_append); } > $@ 459 460quiet_cmd_zstd22 = ZSTD22 $@ 461 cmd_zstd22 = { cat $(real-prereqs) | $(ZSTD) -22 --ultra; $(size_append); } > $@ 462 463# ASM offsets 464# --------------------------------------------------------------------------- 465 466# Default sed regexp - multiline due to syntax constraints 467# 468# Use [:space:] because LLVM's integrated assembler inserts <tab> around 469# the .ascii directive whereas GCC keeps the <space> as-is. 470define sed-offsets 471 's:^[[:space:]]*\.ascii[[:space:]]*"\(.*\)".*:\1:; \ 472 /^->/{s:->#\(.*\):/* \1 */:; \ 473 s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \ 474 s:->::; p;}' 475endef 476 477# Use filechk to avoid rebuilds when a header changes, but the resulting file 478# does not 479define filechk_offsets 480 echo "#ifndef $2"; \ 481 echo "#define $2"; \ 482 echo "/*"; \ 483 echo " * DO NOT MODIFY."; \ 484 echo " *"; \ 485 echo " * This file was generated by Kbuild"; \ 486 echo " */"; \ 487 echo ""; \ 488 sed -ne $(sed-offsets) < $<; \ 489 echo ""; \ 490 echo "#endif" 491endef 492